1. Field of the Invention
The present invention relates to laser cutting, and particularly to an apparatus and method for controlling laser cutting through surface plasma monitoring during laser gas-assisted cutting.
2. Description of the Related Art
Laser cutting is a technology that uses a laser to cut materials, and is typically used for industrial manufacturing applications. Laser cutting is performed by directing the output of a high power laser, by computer, at the material to be cut. The material then either melts, burns, vaporizes away, or is blown away by a jet of gas, leaving an edge with a high quality surface finish. Industrial laser cutters are used to cut flat-sheet material as well as structural and piping materials.
In laser cutting, the cutting speed, feed rate, beam geometry, beam intensity, beam focusing, beam/workpiece material, type of workpiece material, and positioning accuracy all affect the tolerances and surface finish of a process. Additionally, during gas-assisted laser cutting, the assisting gas, such as oxygen mixed with argon, produces a plume of surface plasma at the heated surface of the workpiece. The surface plasma production is an unwanted effect, in that the plasma serves to cut the workpiece in unwanted, and generally uncontrollable, ways, thus enhancing sideways burning and thermal erosion around the cut edges of the workpiece. This lowers the quality of the end product.
Thus, an apparatus and method for controlling laser cutting through surface plasma monitoring solving the aforementioned problems is desired.